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Emergent symmetry in quantum phase transition:From deconfined quantum critical point to gapless quantum spin liquid

Science Bulletin 2024年第2期69卷 190-196页

作者： Wen-Yuan Liu Shou-Shu Gong Wei-Qiang Chen zheng-Cheng gu Department of Physics The Chinese University of Hong KongHong KongChina Division of Chemistry and Chemical Engineering California Institute of TechnologyPasadena CA 91125USA School of Physical Sciences Great Bay UniversityDongguan 523000China Great Bay Institute for Advanced Study Dongguan 523000China Department of Physics and Shenzhen Institute for Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

The emergence of exotic quantum phenomena in frustrated magnets is rapidly driving the development of quantum many-body physics,raising fundamental questions on the nature of quantum phase transitions.Here we unveil the behaviour of emergent symmetry involving two extraordinarily representative phenomena,i.e.,the deconfined quantum critical point(DQCP)and the quantum spin liquid(QSL)state.Via large-scale tensor network simulations,we study a spatially anisotropic spin-1/2 square-lattice frustrated antiferromagnetic(AFM)model,namely the J1x-J1y-J2 model,which contains anisotropic nearestneighbor couplings J1x,J1y and the next nearest neighbor coupling J2.For small J1y/J1x,by tuning J2,a direct continuous transition between the AFM and valence bond solid phase is observed.With growing J1y/J1x,a gapless QSL phase gradually emerges between the AFM and VBS phases.We observe an emergent O(4)symmetry along the AFM–VBS transition line,which is consistent with the prediction of DQCP theory.Most surprisingly,we find that such an emergent O(4)symmetry holds for the whole QSL–VBS transition line as well.These findings reveal the intrinsic relationship between the QSL and DQCP from categorical symmetry point of view,and strongly constrain the quantum field theory description of the QSL phase.The phase diagram and critical exponents presented in this paper are of direct relevance to future experiments on frustrated magnets and cold atom systems.

关键词： Tensor network Quantum phase transition Emergent symmetry Quantum spin liquid Deconfined quantum critical point Anisotropic

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Byzantine Robust Federated Learning Scheme Based on Backdoor Triggers

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Computers, Materials & Continua 2024年第5期79卷 2813-2831页

作者： zheng Yang Ke gu Yiming Zuo School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China

Federated learning is widely used to solve the problem of data decentralization and can provide privacy protectionfor data owners. However, since multiple participants are required in federated learning, this allows attackers tocompromise. Byzantine attacks pose great threats to federated learning. Byzantine attackers upload maliciouslycreated local models to the server to affect the prediction performance and training speed of the global model. Todefend against Byzantine attacks, we propose a Byzantine robust federated learning scheme based on backdoortriggers. In our scheme, backdoor triggers are embedded into benign data samples, and then malicious localmodels can be identified by the server according to its validation dataset. Furthermore, we calculate the adjustmentfactors of local models according to the parameters of their final layers, which are used to defend against datapoisoning-based Byzantine attacks. To further enhance the robustness of our scheme, each localmodel is weightedand aggregated according to the number of times it is identified as malicious. Relevant experimental data showthat our scheme is effective against Byzantine attacks in both independent identically distributed (IID) and nonindependentidentically distributed (non-IID) scenarios.

关键词： Federated learning Byzantine attacks backdoor triggers

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Advances of biomarkers in nasopharyngeal carcinoma’s early detection

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Science Bulletin 2024年第2期69卷 141-145页

作者： Xiao-Hui zheng Allan Hildesheim Wei-hua Jia State Key Laboratory of Oncology in South China Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and TherapyGuangdong Provincial Clinical Research Center for CancerSun Yat-sen University Cancer CenterGuangzhou 510060China Costa Rican Agency for Biomedical Investigation INCIENSA FoundationSan Jose 10108Costa Rica

Nasopharyngeal carcinoma(NPC),a highly invasive and metastatic cancer,is widely prevalent in South China,Southeast Asia,and North Africa.NPC patients with stages I and II are often asymptomatic.Therefore,NPC patients are usually diagnosed with advanced-stage(stages III and IV)at their first visit.Detection of NPC at early stage is the key to improve the survival of patients.Epstein-Barr virus(EBV)plays an essential role in NPC occurrence in endemic areas.EBV-based biomarkers,including EBV antibody in serum and EBV DNA in plasma,have been specifically proposed for NPC early detection.Herein,we summarize recent advances in biomarkers for the early detection of NPC.

关键词： patients nasopharyngeal Nasopharyngeal

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Mechanism Design for Ancillary Service Market Considering Social Welfare and Fairness

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1000-1010页

作者： Zhi Wu Yuanxi Wu Wei gu zheng Xu Shu zheng Jingtao Zhao School of Electrical Engineering Southeast UniversityNanjing 210096China NARI Technology Co. Ltd.Nanjing 211106China IEEE CSEE

Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the DN.In the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of aggregators.Unlike existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment rule.The proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service market.It is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is presented.Moreover,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private parameters.Therefore,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual rationality.Simulation results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.

关键词： Aggregator ancillary service market distributed mechanism fairness mechanism design

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Small-sized Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C for efficient alkaline and acidic hydrogen evolution reaction by an anchoring calcination strategy

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 95-103页

作者： Jianxia gu Ying Zhu Haiyan zheng Chunyi Sun Zhongmin Su Department of Chemistry Xinzhou Normal UniversityXinzhou 034000China School of Chemistry Northeast Normal UniversityChangchun 130024China

A novel,cheap and highly efficient Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C nanocomposite has been successfully constructed through simple one-step carbonization method in a nitrogen atmosphere.Polyethyleneimine in the precursor can effectively anchor molybdenum-based Keggin-type polyoxometallate and NiCo-layered double hydroxide through electrostatic and coordination interactions,which avoids the aggregation of catalyst particles during the pyrolysis process.After optimization,the obtained Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C possesses small size(3-8 nm),large specific surface area and hierarchical pore structure.More importantly,Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C presents remarkable hydrogen evolution reaction activity with low overpotentials in 0.5 mol·L^(-1)H_(2)SO_(4)(102.3 mV)and 1 mol·L^(-1)KOH(95 mV)to afford the current density of 10 mA·cm^(-2),as well as small Tafel slopes of 82.49 and 99.92 mV·dec^(-1),respectively.Simultaneously,this catalyst also shows outstanding stability for 12 h without a significant change in current density.The excellent catalytic performance of Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C can put down to the synergistic effect between multiple components and the small size of the catalyst.This work provides unique insights into the preparation of efficient transition metal-based catalysts for HER.

关键词： polyoxometallates layered double hydroxide transition metal-based electrocatalysts hydrogen evolution reaction

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Spatiotemporal Changes of Snow Depth in Western Jilin,China from 1987 to 2018

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Chinese Geographical Science 2024年第2期34卷 357-368页

作者： WEI Yanlin LI Xiaofeng gu Lingjia zheng Zhaojun zheng Xingming JIANG Tao Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China Changchun Jingyuetan Remote Sensing Experiment Site Chinese Academy of SciencesChangchun 130102China College of Electronic Science and Engineering Jilin UniversityChangchun 130012 National Meteorological Satellite Meteorological Center Beijing 100081China

Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.

关键词： snow cover snow depth(SD) climate changes passive microwave(PMW) western Jilin,China

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Electrolyte effect on electrochemical behaviors of manganese fluoride material for aqueous asymmetric and symmetric supercapacitors

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Rare Metals 2024年第3期43卷 1048-1061页

作者： zheng-hua He Jian-Fei Gao Ling-Bin Kong State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of TechnologyLanzhou730050China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou730050China

Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical HSC.However,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for HSC.The MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)NaOH.Furthermore,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle capability.Meanwhile,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle stability.This work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.

关键词： Manganese fluoride Potential window Hybrid supercapacitors Electrochemical performance

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Numerical Simulation on Partially Liquid-Filled Sloshing with Baffle Under Different Density Ratios by the CLSVOF/IB Method

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China Ocean Engineering 2022年第6期36卷 922-932页

作者： gu zheng-hua WANG Ting-hui WU Tie-cheng LI Yu-long College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China Technology Centre for Offshore and Marine Singapore(TCOMS)Singapore Southern Marine Science and Engineering guangdong Laboratory(Zhuhai) Zhuhai 519000China

The density and viscosity ratios on partially liquid-filled sloshing with baffle have been investigated numerically in this study.As the key to success in the present simulation,the Coupled Level Set and the Volume of Fluid(CLSVOF)method and the Immersed Boundary(IB)method are used to capture gas/liquid and fluid/structure interfaces,respectively.Within the CLSVOF method,surface normal in weighting factors is calculated by the level set function,resulting in a more accurate solution.Furthermore,the Tangent of Hyperbola for INterface Capturing(THINC)coupled with the Weighted Linear Interface Calculation(WLIC)scheme is used for capturing moving interface.As a standard practice,we first validate the code by comparing it with experimental results of liquid sloshing,which involves large deformation of interface.In addition to the validation study of the present method,the problems of liquid sloshing with baffle are investigated to understand kinematics and dynamics behaviors under different density and viscosity ratios.

关键词： liquid sloshing CLSVOF immersed boundary interface density ratio

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Analysis and monitoring of drug therapy in a patient with peptic ulcer complicated by infection:A case report

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World Journal of Clinical Cases 2024年第8期12卷 1530-1535页

作者： Yan-Ping Gou Yue huang Li Chen Wei zheng Yun-hua zheng The Second People’s Hospital of Meishan City&Renshou County People’s Hospital Meishan 620500Sichuan ProvinceChina Quality Evaluation and Medical Record Management The Affiliated Hospital of Southwest Jiaotong University&The Third People's Hospital of ChengduChengdu 610000Sichuan ProvinceChina Patriotic Health Campaign Qionglai City Health BureauChengdu 610000Sichuan ProvinceChina

BACKGROUND The role of primary-level medical pharmacists in medical institutions in China is limited;therefore,it is necessary to explore the role of pharmacists in the process of drug treatment.CASE SUMMARY A Chinese pharmacist participated in the complete treatment of a patient with a duodenal ulcer.The rationale for drug treatment was evaluated,and adjustments were made to the antacid and anti-infective regimen,as well as the dose and frequency of administration.Body temperature,routine blood examination,and adverse drug reactions were strictly monitored.During treatment,the pharmacist recommended anti-infective therapy with ampicillin-sulbactam,which effectively controlled the infection.Additionally,the pharmacist suggested changing famotidine to lansoprazole for acid suppression and gastroprotective treatment,combined with Chinese patent medicine such as Kangfuxin Liquid.This is the first case report of a pharmacist in primary-level medical institutions adjusting drug use for patients with duodenal ulcer and pulmonary infection.CONCLUSION A pharmacist participated in the treatment process,provided individualized medication adjustment,and achieved good clinical results.

关键词： Ampicillin-sulbactam Famotidine Lansoprazole Kangfuxin Liquid Chinese pharmacist Case report

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Hybrid tri-memristor hyperchaotic map and application in Wasserstein Generative Adversarial Nets

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Science China Technological Sciences 2024年第6期67卷 1855-1865页

作者： gu Yang BAO Han YU XiHong hua ZhongYun BAO BoCheng XU Quan School of Microelectronics and Control Engineering Changzhou University School of Computer Science and Technology Harbin Institute of Technology

Inspired by basic circuit connection methods, memristors can also be utilized in the construction of complex discrete chaotic systems. To investigate the dynamical effects of hybrid memristors, we propose two hybrid tri-memristor hyperchaotic(HTMH)mapping structures based on the hybrid parallel/cascade and cascade/parallel operations, respectively. Taking the HTMH mapping structure with hybrid parallel/cascade operation as an example, this map possesses a spatial invariant set whose stability is closely related to the initial states of the memristors. Dynamics distributions and bifurcation behaviours dependent on the control parameters are explored with numerical tools. Specifically, the memristor initial offset-boosting mechanism is theoretically demonstrated, and memristor initial offset-boosting behaviours are numerically verified. The results clarify that the HTMH map can exhibit hyperchaotic behaviours and extreme multistability with homogeneous coexisting infinite attractors. In addition, an FPGA hardware platform is fabricated to implement the HTMH map and generate pseudorandom numbers(PRNs)with high randomness. Notably, the generated PRNs can be applied in Wasserstein generative adversarial nets(WGANs) to enhance training stability and generation capability.

关键词： memristor hybrid tri-memristor map spatial invariant set hyperchaos extreme multistability generative adversarial nets

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